The identity of the suspect pictured carrying bloodied knives in the aftermath of the murder of a British soldier is Michael Olumide Adebolajo, Guardian sources have confirmed.

Adebolajo was an ordinary British schoolboy; born in Lambeth in December 1984, he grew up in Romford, travelled to school on the bus, played football and appeared to have a lot of friends.

His family – who are of Nigerian origin — were practising Christians, attending the local church. He has two siblings; a sister and a brother. Both boys went to Marshalls Park school in Romford. At 16, Adebolajo moved to Havering sixth form college, and then at 18 attended Greenwich University, where he lived in student accommodation in 2004 and 2005.

Friends from Marshalls Park school talked of how he was an ordinary student who got the bus, played football, and "jacked" a few phones.

Speaking on social media, the friends expressed shock that the boy they went to school with was at the centre of a murder investigation after the events of Wednesday.

"We left year 2001," one said. "And he was always a good guy at school, do anything for anyone."

Another added: "They used to live … 2 minutes from marshals they had a garage on the side of the house an' [the brother] had a little telly an' that in there an' loads of people used to go round there; from what I remember they were nice boys."

A former neighbour of the family remembered them as friendly and welcoming churchgoers.

The man, who asked not to be named, said his wife used to give Adebolajo's mother – who he remembered as working for social services – a lift to church.

"They were very pleasant, a very ordinary normal family," he said.

But Graham Silverton, 63, who has lived in the street for 25 years, said neighbours had a particularly bad experience with Adebolajo when he was a teenager. He said one of the neighbours' children, a teenage girl, had gone to the Adebolajos' door to retrieve a ball kicked into their garden and was insulted and punched by Adebolajo.

The family lived in Romford until around 2004, when it is understood his parents divorced and they moved to Lincoln.

Police had sealed off Adebolajo's sister's home in Romford on Thursday and Metropolitan police officers travelled to Lincoln on Wednesday night to carry out searches at the family home in Saxilby.

Counter-terrorism officers and the security services are examining Adebolajo's links to the banned extremist group al-Muhajiroun. It is understood he was radicalised around 10 years ago, changing his name to Mujaahid, which means "one who engages in jihad".

Friends at his school said they knew nothing of his conversion to Islam.

The Guardian understands that both Adebolajo and the other suspect have featured in counter-terrorism investigations over the last eight years.

But it is understood that, while they were known to the police and security services, they were considered peripheral figures among the many extremists whose activities cross the radar of investigators.

Adebolajo was frequently seen in Woolwich handing out Islamist literature in the High Street.

Anjem Choudary, the former leader of al-Muhajiroun, has confirmed that he knew Adebolajo, who was pictured on video in the immediate aftermath of the horrific killing waving a cleaver with bloodied hands.

Choudary said Mujaahid had converted to Islam in 2003 and was a British-born Nigerian. He said he had attended meetings of al-Muhajiroun from around 2005-11, but stopped attending the meetings, and those its successor organisations, two years ago.

At the meetings he heard an interpretation of Islam preached by the group's founder, Omar Bakri Mohammed, which many Muslims would consider extreme.

Choudary said: "He was on our ideological wave-length."

He added that Adebolajo was very quiet and that Mohammed, now believed to be abroad, also remembered Adebolajo attending events held by the group.

Choudary said he was shocked by the attack, and that he believed Muslims in Britain were covered by a covenant of security, meaning that they should not wage violence here, in return for safety.

"I believe that this is not allowed for me to engage in. I would not encourage someone to do it," he said.

"I don't think it helps to condemn or condone. I condemn the hundreds of thousands slaughtered by British and American foreign policy."

Al-Muhajiroun was banned after the 7 July 2005 terrorist attacks on London, and it kept changing its name to beat the ban. The successor groups were also banned.

One of them, Islam4UK, threatened to target the military town of Royal Wootton Bassett for protests.

Bakri was banned from Britain in 2005 by the then home secretary, Charles Clarke, on the grounds that his presence in the country was "not conducive to the public good".